Prefabricated roof section



P. B. ATTWELL `PREFABRIGATED ROOF 4SECTION `Filed Dec. 6, 1944 Dec. 30, 1947.

INVENTOR.

P. ob inve/1 M www /TTONASY Fay, z

Patented Dec. 30,:11947 Plri-ii`NTl orFlcE j 'LPREFAEKICATEQRQQF SECHQN- P..Bob` Anwen, seattle, wash.y

Application December 6, 1

f l-Claim.- (Cl This invention relatesto a prefabricated'wo'od roof section or panel for use in building construction and. an' object: ofithi'sv inventioniis fto' provide a simple' and .inexpensive wood roof'p'anel' that is veryv strong inconstruction,thatcan 'bef 5 very quickly and easily installed in .ai roofi under adverse weather conditions'and vthatwill 'provideI a moisture tight` and wind tight `r'obf whiohiwill beA long lasting, and durable under: substantially all climatic conditions.; Lr

In certain types of prefabricatedbuildings itisdesirableto -use rcurvedroofs. to obtainimaximum; room in abuilding of given height and atthe. same time provide aroof ofgreatstrengthithat will withstand heavy; wind' andsnow loads. ARes 15` quirements of these xpreialrricatedA roofs are that.: they-should Abe highly resistant to wind and moisture, that they should be capable of being quickly and easily assembled or erected on the lob and that they should be constructed so that 2U they can be assembled and the roof completed in high winds and rainy weather. Also as buildings of this type are. frequently shipped long distances it is highly desirable for these prefabricatedroofsH l. to be made in sections that arefofrelatively light 2'5c weight and that are compact fin the knocked down or disassembled condition in which they are shipped. f4 f Another object ofv this invention is to provide a Wood rOOf Sst9etiiat-isnedeeup of twobver- 3'0' lapped sheets of plywood adhesively secured together in facev to faceA relation, said two sheets being slightly offset as respects each other to' provide edge flanges 4extending;entirely around K each roof section, .said edge flanges being formed by the overhanging portions of the plywood sheetsv and being offset substantially one-haltthe thickness of the roof section and being adapted to overlap the flanges of adjacent roof sections when a plurality of these roof sections are as- 40 sembled to form a roof.

Another object is to provide a wood roof section that is built to a proper curvature for a curved roof and that is permanently held to this curvature by stiiener rib means embodied in the roof section, said stifrener rib means also serving to greatly stiien and strengthen the roof section.

Other objectsare to provide a curved roof section that is made from whole plywood sheets of standard size thereby minimizing waste of wood and to construct this roof section without the use of nails or screws or any securing means eX- cept adhesive.

Other objects of the invention will be apparent 944, Serial No. 566,800

from the following description taken in connec tion with the accompanying drawings.

' In 'the'drawings f n Figure 1 is a plan' view showing the outer side@ of a'ro'ongp'anel constructed in accordance with' this invention.

"Fig, 2 is a similar plan View showing the 'inner' OI under side of a roong panel.

Fig. 3 is a sectional view of sa on broken' line 3 3 of Fig. 1.

Fig." 4 is a. fragmentary visometric view on a, larger scalefthan Figs. 1, 2 rand 3 showing thev manneroiV applyingtheseV panels to a roof.

`Figi'5 is an enlarged fragmentary sectional View Vtaken substantially on broken line 5 5 o'f Figli.Av`

Like reference numerals design throughout the several views. l

Each roof section or panel comprises two sheets I and II of' plywood secured together in slightly" olset face to face relationby waterproof adhe`' sive I2. The"adhesive I2is shown inssomewhat exaggerated thickness in Fig.' 5. vEach ro'oi sec-- tion is 'provided on its inner side" with a plurality of spacedapart transverse stiffener rlos'IBthatl are secured by adhesive 'I4'. Fig. 5', to`theinner-'- most-sheet H yof plywood: i'

-The two-plywood sheets IIliand yII are vslightly id panel taken ate like part'sf A oiset relative4 to eachother, both-longitudinally andfftransversely"to provide A'flange portions I 5: which extend entirely around eachsection; One" end'flange and one side ange of each `roof seca' tion are'lformed by vone sheet I il andthe vother end ange and'side flange of' the roof'section"` are formed by theotherply-woodsheet I I.' Theangesformed by the respective sheets IIB and `II are" oiset and are arranged to intert andA over# lap and form lap joints when a plurality of these roof sections are laid to form a roof.

A suitable water repellant material, such as roong paper I6 is secured by adhesive I1, such as hot asphalt, to the outer surface of the outermost sheet I0 of plywood. 'I'his outer covering of Water repellant material covers the entire outer surface of the sheet I0 of plywood.

In making up the panels or roof sections I preferably place water resistant adhesive or glue between sheets I0 and II and between ribs I3 and sheet II. I then place these parts I0, II and I3 under pressure which bends them to a desired curvature, as by putting them in a press, and holds them under this pressure and curvature until the Yadhesive has rmly set. When the pressure is released the roof sections will straighten out to a certain extent but the initial curvature is enough greater than the desired curvature so that the curvature of the panels when cured will be correct and this final curvature will be permanently retained. A number of roof sections may be placed in a press in superposed re lation and glued up at the same time.

I nd it convenient to use standard plywood sheets four feet wide and eight feet long and to offset these sheets enough to provide anges I5 of about one inch in width. However plywood sheets of different size may be used and the width oi the flanges I5 may be varied.

The roof sections or the wooden parts from which such sections are constructed are preferably treated with a tocsic sealer which both hardens and seals the wood and makes the same more resistant to fungus and vermin and the like.

The roof sections are transversely curved and the stiffener ribs extend crosswise of these roof sections and permanently maintain the curvature of the roof sections. One stiener rib is provided near each end of the panel but far enough nwardly from the end of the panel or roof section to afford room for the end portion of said panel or roof section to rest on a support, such as a curved rafter or arch support I8 shown in Fig. 4. As many transverse stifener ribs as desired may be provided at spaced intervals between the two end stifiener ribs I3. The curved rafters or arch supports I8 may be made of laminated Wood as shown in Fig. 4. Also purlins 2|, Fig. 4, are preferably provided at right angles to the curved arch supports I8 and the overlapping lateral edge portions of the roof sections rest on and are secured to these purlins. Preferably the overlapping marginal portions of the roof sections are secured to the arch members I8 and purlins 2l by nails or screws.

After the roof sections have been properly secured to the roof framing the waterproong of the roof is completed by applying over the a'djoining edge portions of the panels a Water repellent mastic I9 and then applying and pressing down onto this mastic I9 a strip of open mesh material 20 such as cotton or cotton impregnated with tar or asphalt. This mastic and cotton mesh strip can be applied in the rain if necessary.

In the use of these roof panels or sections in forming a roof the sections are relatively easy and fast to lay and the anges I5 always form lap joints at all places where two panels adjoin. The panels are of strong and substantial construction and can be applied to a roof in windy and rainy weather. The roofing paper I6 is a part of the prefabricated construction of each roof panel or section and this eliminates separate handling of roong paper at the time the roof is constructed. This is a very great advantage in windy weather as high winds make it substantially impossible to apply ordinary rolled roofing to a roof. Also the mastic and cotton mesh can be put on in the rain thus making it possible to complete the waterproofing of a roof in heavy Winds and rain.

Obviously changes in the construction of this roof section may -be made within the scope and spirit of the following claim.

I claim:

As an article of manufacture a prefabricated roof section of large area comprising two rectangular sheets of standard plywood of equal size adhesively secured together in face to face contact and in slightly offset echelon relation provi'ding along all sides 0f said roof section flanges formed by overhanging portions of the sheets, each sheet of plywood being of standard size and formed of a plurality of sheets of wooden veneer, the flanges along .two adjacent sides of the roof section being oiset relative to the flanges along the other two adjacent sides of the roof section to provide overlapping flanges along all adjoining edges of roof sections when a plurality of the roof sections are assembled to form a roof; transverse stiffener ribs adhesively secured to the inner surface of the roof section permanently holding said roof section under transverse curvature whereby installation of said roof section in a roof of corresponding curvature is facilitated; and roofing paper adhesively secured to ythe outer surface of said roof section providing a completelv finished externally Weatherproofed strong and durable roof section of large area for quick and easy incorporation into a roof. v

P. BOB ATTWELL.

REFERENCES CITED The following references are of record in the ile of this patent:

UNITED STATES PATENTS Number Name Date 322,990 Sporny July 28, 1885 1,954,095 Osgood Apr. 10, 1934 2,278,956 Wagner Apr. 7, 1942 2,283,582 Scherer May 19, 1942 2,303,003 Rumsey Nov. 24, 1942 2,336,191 Rose Dec. 7, 1943 FOREIGN PATENTS Number Country Date 540,903 Great Britain 1941 OTHER REFERENCES American Builder, page 77, Dec. 1937 issue. 

